自循环机匣处理轴向位置影响扩稳能力的机理

Mechanism of affecting ability of stability enhancement with varying axial position of self-recirculating casing treatment

为了揭示自循环机匣处理轴向位置影响压气机稳定性的流动机理,采用非定常数值方法研究了3种不同轴向位置对机匣处理(CT)扩稳能力的影响,结果表明:机匣处理喷气装置离叶顶前缘最近且在叶顶前缘上游的扩稳能力最强,喷气装置在叶顶前缘正上方的次之,喷气装置在叶顶前缘上游较远处的最弱,对应机匣处理获得的综合失速裕度改进量分别为9.40%,7.09%,5.49%.通过详细地分析压气机叶顶流场表明:喷气装置离叶顶前缘最近且在叶顶前缘上游的机匣处理施加有利影响程度最高的范围刚好覆盖叶顶前缘处,此处是引起转子失速的关键部位,因此抑制叶顶间隙泄漏流造成的堵塞的效果最好,对应的扩稳能力在3种机匣处理中最强.

The unsteady numerical investigation of three kinds of self-recirculating cas- ing treatments was performed to explore the mechanism of affecting the ability of improving compressor stall margin with changing axial position of casing treatment （CT）. Results showed that the ability of improving stall margin was best when the injecting part of CT was close to the blade tip leading edge, and also located in upstream blade inlet. The ability be- came low by changing the axial position of CT to make the injecting part above the blade tip leading edge. It became lower by moving the injecting part away from the blade tip leading edge along upstream direction, and the corresponding stall margin improvement gained with three kinds of casing treatments was 9.40%, 7.09o//00 and 5. 490//oo respectively. When the in- jecting part of CT was close to the blade tip leading edge, and located in upstream blade in- let, the level of positive effect created by CT was highest in the blade tip leading edge and the stall of rotor happened in this pivotal zone. Consequently the inlet blockage caused by the low energy tip clearance leakage flow was restrained most effectively, and the corresponding ability of increasing rotor stable operating range was highest among three kinds of casing treatments.